Analyze the results of the donation campaign

The goals would be:

• Understand how we could improve our donation page and user scenario
• Understand which source of clicks and incentives work the best
• Have some metrics to know if we are doing better or worse next time

We could analyze:

• Number of donors
• Average donation amount
• Calendar wrt other campaigns
• Days with more donations
• Metrics they use at Tor and Wikipedia
• Referrers who work the best
• Convertion rate (across different referrers)

Parent Task: #9855 (closed)

Original created by @sajolida on 12082 (Redmine)